1. Field of the Invention
The present invention relates to orthodontic modeling methods and materials.
2. Background Information
As is the case with any service-based occupation, time is money in dentistry and orthodontics. Therefore, any method or product which expedites the delivery of services in the dental and orthodontics fields will translate into greater profitability for practitioners and, perhaps, lower cost of care for patients and insurance companies.
For a number of dental and orthodontic procedures, dental models or xe2x80x9cimpressionsxe2x80x9d are made. Models are made first by producing a rough, negative topological impression. This is taken with the assistance of a standard perforated metal or plastics tray, wherein for the impression material alginate, palgate, etc. are used. Then the topological impression is used to form a cast using hard plaster, which produces a positive topological model, which, in turn, reflects the rough topology found in the mouth or on the biting surfaces of the patient, i.e. existing or absent teeth, the shape of the jaw crest and the mucous membranes, irregularities, etc.
For certain procedures, a number of additional steps are involved, and include the creation of a negative topological tray or xe2x80x9cfunctional trayxe2x80x9d, a precise topological or xe2x80x9cfunctionalxe2x80x9d impression, a precise topological or xe2x80x9cfunctionalxe2x80x9d model, and an occlusion mold or bite impression, all, in some cases, leading to the creation of a final denture, plate or other dental or orthodontic appliance. However, the step(s) in which impressions in trays are used to produce plaster casts are those processes with which the present product and method are concerned.
A consequence of the inevitable design of impression trays used to make lower teeth impressions is that a large space or void exists where the tray is contoured for receiving a patient""s tongue during an impression step. If left unoccluded, this void will fill with plaster during the casting processxe2x80x94plaster which must later be painstakingly removed to acquire adequate access and visualization of the teeth in the resulting plaster model.
Some dental and orthodontic offices use alginate (the same material that is used as the actual impression) to fill this void in the lower impression tray and, thereby, partially avoid the excess plaster problem. This is not an efficient or cost-effective solution to the problem. Alginate is not forgiving of mixing errors, often sets up more quickly than is consistent with its use after an impression is taken and to fill the void in the lower teeth tray for casting, and is somewhat expensive. Other dental and orthodontic offices simply do nothing, and, after a plaster model is made, carefully trim away the excess plaster to gain access and visualization to the pertinent portions of the model. This latter approach is extremely time-consuming and even poses a potential health risk due to the dust produced by the plaster removal process.
Another, separate problem which arises in the context of making dental models relates to unintended gaps or voids in the plaster model which is produced as part of the progression to a final dental appliance.
When plaster models are produced, inevitably there are gaps and voids formed by bubbles, air pockets, molding technique mistakes, etc. In addition, certain gaps which are accurate reflections of the patient""s mount or dental structures will be filled when making the plaster model for the ultimate production of dental appliancesxe2x80x94missing natural teeth, for example.
Such gaps or voids must be filled and properly contoured before using the model for further development of a dental appliance. Otherwise, a new model must be madexe2x80x94a considerable waste of time and expense, and one sometimes involving calling the patient back into the dental office for a new impression.
In view of the above, it would be very beneficial to dental and orthodontic practitioners to provide a method and related product which can be used in avoiding the excess plaster problems which are inherent in the use of lower teeth impression trays, and which method and related product is simple to use, very cost-effective, environmentally benign, and at least as effective as any known method or product. In addition, it would likely, but independently well-serve such professionals to provide a method and associated material which could be used to quickly, conveniently and cost-effectively fill voids in plaster models, caused by bubbles, air pockets, etc. in order to avoid having to replace the defective models, or consume expensive materials which are difficult to work in this context.
In view of the foregoing, it is an object of the present invention to provide a filler material for use with dental model impression trays in occluding space which is otherwise filled with excess plaster during a plaster model casting process.
It is another object of the present invention to provide a method for producing a filler material which is useful in occluding spaces in dental impressions and appliances in which, without use of such filler material, unwanted plaster would reside after the plaster pouring step of making a dental impression, such process resulting in an optimally tacky dough-like material which is inexpensive to produce and purchase, is pre-mixed, requires no set up time, is water soluble for easy cleanup, is easy to form to any desired shape, has a very long shelf life, is environmentally benign, and which exhibits a desirable, slightly sticky or tacky quality which, unlike PLAYDOUGH-like products, will adhere to dental impression appliances to a degree necessary to remain in-place during use, but not so tacky as to be difficult to remove or for a user to disengage from hands and fingers.
It is another object of the present invention to provide a method by which space within the bounds of a lower teeth impression tray, which is otherwise filled with excess plaster during a plaster model casting process, is occluded with a convenient and cost-effective dough-like filler material thereby obviating the problems left unsolved in the prior art.
It is another object of the present invention to provide a method and associated material which could be used to quickly, conveniently and cost-effectively fill voids in plaster models, caused by bubbles, air pockets, etc. in order to avoid having to replace the defective models, or consume expensive materials which are difficult to work in this context.
The product of the present invention is a dough-like filler material which is used to temporarily occlude or occupy the space or void which is provided in the lower teeth impression tray for use in dental modeling for accommodating a patient""s tongue. The dough-like filler material is used after an initial impression is taken and before plaster is applied to form a positive model. The presence of the dough-like filler material during the plaster casting process prevents the formation of plaster accumulations which interfere with access and visualization of the teeth portions of a plaster model.
Extensive development and research efforts by the present inventors reveals that not just any filler material will work. The formulation and method of producing the product in its present form is the result of countless variations of constituents and processing methods. Earlier formulae and/or processing methods resulted in filler which was too sticky, not sticky enough (would not stay in-place on impression appliances), was too stiff to work with, and/or lacked adequate shelf life to be a viable product for other than instantaneous use after making the product.
The use of the present dough-like filler material as described provides a highly cost-effective alternative to the prior art approaches of using alginate (or other impression material) to occlude the lower teeth tray void, or the use of no occluding material followed by manual carving away of excess plaster.
In addition to the foregoing, the present dough-like filler material can be used to quickly, conveniently and cost-effectively fill voids in plaster models, caused by bubbles, air pockets, etc. in order to avoid having to replace the defective models, or consume expensive materials which are difficult to work in this context.
The dough-like filler material of the present invention is, unlike conventional impression material, inexpensive to produce and purchase, is pre-mixed, requires no set up time, is water soluble for easy cleanup, is easy to form to any desired shape, has a very long shelf life, and is in environmentally benign. It furthermore exhibits a desirable, slightly sticky or tacky quality which, unlike PLAYDOUGH-like products, will adhere to dental impression appliances to a degree necessary to remain in-place during use, but not so tacky as to be difficult to remove or for a user to disengage from hands and fingers.
Practice of the present invention will save time and money in the dental and orthodontic practices and pull solve problems not heretofore solved by any known prior art approach.